During exploratory endoscopic procedures such as colonoscopy, bronchoscopy, endoscopic retrograde cholangiopancreatography (ECRP) or other endoscopic procedures, it is desirable to locate any lesions or other areas that are of interest such as, for example, precancerous changes, bleeding sites, polyps, nodules, or other areas of interest. Traditional endoscopic examination consists entirely of an optical examination of the conduit or area of interest within the anatomy of the patient. More recently, virtual examination has become more popular. In virtual endoscopy, computerized tomography (CT), magnetic resonance (MR), ultrasound, or other diagnostic imaging methods are first used to locate a suspect lesion either with or without the assistance of a computer algorithm (e.g., “CAD” or computer assisted diagnosis). Lesion candidates are then inspected optically and treated or biopsied as deemed appropriate by the physician.
During optical endoscopic examination, it is important to locate all flagged suspicious regions (e.g., lesions or other areas of interest) and examine them. In practice, this can be difficult because there is no way to easily register image-based data regarding suspect lesions to the patient space (e.g., the real world location of the suspected lesions). Often the length of the endoscope from the insertion point into the patient is the only indication of the location of suspect lesions. Typically this indication is extremely crude, averaging 10 centimeters (cm) or more of error. In arborized tissues, such as, the bronchial pathways of the lungs, physicians frequently become disoriented and enter a branch other than the desired one.
The invention is designed to assist in the optical localization of suspect lesions or other areas of interest that are initially detected using virtual colonoscopy or other virtual endoscopy. This invention enables the physician performing the examination to more efficiently locate suspicious lesion candidates from imaging scans, such as CT, MR, ultrasound, or other imaging scans. Once the position of the candidate lesion or other area of interest is determined from the imaging scan (either manually, computer assisted, or through the use of a fully automated CAD software) the (x, y, z) location of the candidate will be recorded in image (i.e. CT space) or in some other convenient form. The system then enables these locations to be indicated to the physician during a conventional optical endoscopic exam, increasing the likelihood that he will be able to locate and inspect them. The invention further enables the shape of a flexible endoscope or other instrument to be determined without the use of additional imaging.